Implemented button input using 74HC165 shift registers.

arduino/ShiftInput.cpp

@@ -0,0 +1,75 @@
+/*
+Copyright 2018 Sam Stevens
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+   http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+ */
+
+#include <Arduino.h>
+#include "ShiftInput.h"
+
+ShiftInput::ShiftInput(uint8_t chipCount, uint8_t loadPin, uint8_t clockPin, uint8_t clockInhPin, uint8_t dataPin) {
+  this->input = (uint8_t*)calloc(chipCount, sizeof(uint8_t));
+  this->chipCount = chipCount;
+  this->loadPin = loadPin;
+  this->clockPin = clockPin;
+  this->clockInhPin = clockInhPin;
+  this->dataPin = dataPin;
+  pinMode(loadPin, OUTPUT);
+  digitalWrite(loadPin, HIGH);
+  pinMode(clockPin, OUTPUT);
+  digitalWrite(clockPin, LOW);
+  pinMode(clockInhPin, OUTPUT);
+  if (clockInhPin > 0) {  
+    digitalWrite(clockInhPin, HIGH);
+    pinMode(dataPin, INPUT);
+  }
+}
+
+uint8_t* ShiftInput::getInput() {
+  return this->input;
+}
+
+uint8_t ShiftInput::getChipCount() {
+  return this->chipCount;
+}
+
+bool ShiftInput::updateInput() {
+  //Load values
+  digitalWrite(this->loadPin, LOW);
+  digitalWrite(this->clockPin, HIGH);
+  digitalWrite(this->loadPin, HIGH);
+  digitalWrite(this->clockPin, LOW);
+  
+  bool change = false;
+  uint8_t input = 0;
+  if (this->clockInhPin > 0){
+    digitalWrite(this->clockInhPin, LOW);
+  }
+  for(uint8_t chip = 0; chip < this->chipCount; chip++) {
+    input = 0;
+    for(uint8_t inputBit = 0; inputBit < 8; inputBit++) {
+      input |= (digitalRead(this->dataPin) == HIGH ? 1 : 0) << inputBit;
+      digitalWrite(clockPin, HIGH);
+      digitalWrite(clockPin, LOW);
+    }
+    if (this->input[chip] != input) {
+      this->input[chip] = input;
+      change = true;
+    }
+  }
+  if (this->clockInhPin > 0){
+    digitalWrite(this->clockInhPin, HIGH);
+  }
+  
+  return change;
+}

arduino/ShiftInput.h

@@ -0,0 +1,36 @@
+/*
+Copyright 2018 Sam Stevens
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+   http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+ */
+
+#ifndef UVM_SHIFTINPUT_H
+#define UVM_SHIFTINPUT_H
+
+#include <stdint.h>
+
+class ShiftInput {
+    uint8_t *input;
+    uint8_t chipCount;
+    uint8_t loadPin;
+    uint8_t clockPin;
+    uint8_t clockInhPin;
+    uint8_t dataPin;
+  public:
+    ShiftInput(uint8_t chipCount, uint8_t loadPin, uint8_t clockPin, uint8_t clockInhPin, uint8_t dataPin);
+    uint8_t getChipCount();
+    uint8_t *getInput();
+    bool updateInput();
+};
+
+#endif //UVM_SHIFTINPUT_H

arduino/arduino.ino

@@ -19,15 +19,17 @@ limitations under the License.
  * Hello World: 0x311833021210c0323401411412103416e4203406d400000048656c6c6f20576f726c640a
  */
 
-#include "vm.h"
-#include "console.h"
-#include "memory.h"
+#include "VM.h"
+#include "Console.h"
+#include "Memory.h"
+#include "ShiftInput.h"
 
 VM vm;
 Console console(&vm);
+ShiftInput buttons(1, 14, 15, 0, 16);
 
 //Expecting a Microchip 23LCV512 connected over MOSI/MISO/MCLK
-Memory mem(20000000, MSBFIRST, SPI_MODE0, 4);
+Memory mem(4);
 MemoryCache ICache(64, mem);
 MemoryCache DCache(32, mem);
 
@@ -68,6 +70,17 @@ void setup() {
 
 void loop() {
   console.loop();
+
+  if (buttons.updateInput()) {
+    uint8_t *input = buttons.getInput();
+    for(uint8_t i = 0; i < buttons.getChipCount(); i++) {
+      Serial.print("Button Group ");
+      Serial.print(i);
+      Serial.print(" = ");
+      Serial.print(input[i], BIN);
+      Serial.println();
+    }
+  }
 }
 
 void vm_print_error(uint8_t err) {

arduino/console.cpp

@@ -17,7 +17,7 @@ limitations under the License.
 #include <Arduino.h>
 #include <HardwareSerial.h>
 #include <errno.h>
-#include "console.h"
+#include "Console.h"
 
 Console::Console(VM* _vm) {
   this->state = CONSOLE_NONE;

arduino/console.h

@@ -18,7 +18,7 @@ limitations under the License.
 #define UVM_CONSOLE_H
 
 #include <HardwareSerial.h>
-#include "vm.h"
+#include "VM.h"
 
 enum ConsoleState_t {
   CONSOLE_NONE,

arduino/memory.cpp

@@ -14,9 +14,9 @@ See the License for the specific language governing permissions and
 limitations under the License.
  */
 
-#include "memory.h"
+#include "Memory.h"
 
-Memory::Memory(uint32_t clock, uint8_t bitOrder, uint8_t dataMode, uint8_t csPin) {
+Memory::Memory(uint8_t csPin) {
   //Set cs pin high
   this->csPin = csPin;
   pinMode(csPin, OUTPUT);
@@ -24,7 +24,7 @@ Memory::Memory(uint32_t clock, uint8_t bitOrder, uint8_t dataMode, uint8_t csPin
   //Default to 64k ram
   this->memSize = 0xFFFF;
   //Store spi setting
-  this->setting = SPISettings(clock, bitOrder, dataMode);
+  this->setting = SPISettings(20000000, MSBFIRST, SPI_MODE0);
 }
 
 void Memory::start() {

arduino/memory.h

@@ -43,7 +43,7 @@ class Memory {
     void start();
     void end();
   public:
-    Memory(uint32_t clock, uint8_t bitOrder, uint8_t dataMode, uint8_t csPin);
+    Memory(uint8_t csPin);
     uint16_t getSize();
     void setSize(uint16_t memSize);
     bool init();

arduino/vm.c

@@ -16,7 +16,7 @@ limitations under the License.
 
 #include <stdlib.h>
 #include <string.h>
-#include "vm.h"
+#include "VM.h"
 
 VM *new_vm() {
     VM *vm = calloc(1, sizeof(VM));